INTRODUCTION 57 
the only) part of a Vollstiéndiges Handbuch der Natwryeschichte der Végel 
Europa’s, treating of the Land-birds. In the Introduction to this book 
(p. Xxxvill. note) he expressed his regret at not being able to use as 
fully as he could wish the excellent researches of Nitzsch which were 
then appearing (as has been above said) in the successive parts of Nau- 
mann’s great work. Notwithstanding this, to Gloger seems to belong 
the credit of being the first author to avail himself, in a book intended 
for practical ornithologists, of the new light that had already been shed 
on Systematic Ornithology ; and accordingly we have the second Order 
of his arrangement, the Aves Passerinex, divided into two Suborders :— 
Singing Passerines (melodusx), and Passerines without an apparatus of 
Song-muscles (anomalx)—the latter including what some later writers 
called Picartx. For the rest his classification demands no particular 
remark ; but that in a work of this kind he had the courage to 
recognize, for instance, such a fact as the essential difference between 
Swallows and Swifts, lifts him considerably above the crowd of other 
ornithological writers of his time. 
An improvement on the old method of classification by purely 
external characters was introduced to the Academy of Sciences of Stock- 
holm by Sundevall in 1835, and was published the following year in 
its Handlingar (pp. 43-130). This was the foundation of a more 
extensive work of which, from the influence it still exerts, it will be 
necessary to treat later, and there will be no need now to enter much 
into details respecting the earlier performance. It is sufficient here to 
remark that the author, even then a man of great erudition, must have 
been aware of the turn which taxonomy was taking; but, not being 
able to divest himself of the older notion that external characters were 
superior to those furnished by the study of internal structure, and that 
Comparative Anatomy, instead of being a part of Zoology, was some- 
thing distinct from it, he seems to have endeavoured to form a scheme 
which, while not running wholly counter to the teachings of Com- 
parative Anatomists, should yet rest ostensibly on external characters. 
With this view he studied the latter most laboriously, and certainly not 
without success, for he brought into prominence several points that had 
hitherto escaped the notice of his predecessors. He also admitted among 
his characteristics a physiological consideration (apparently derived from 
Oken!) dividing the class Aves into two sections Altrices and Precoces, 
according as the young were fed by their parents, or, from the first, fed 
themselves. But at this time he was encumbered with the hazy 
doctrine of analogies, which, if it did not act to his detriment, was 
assuredly of no service to him. He prefixed an ‘Idea Systematis’ to 
his ‘Expositio’; and the former, which appears to represent his real 
opinion, differs in arrangement very considerably from the latter. Like 
Gloger, Sundevall in his ideal system separated the true Passerines from 
all other Birds, calling them Volucres; but he took a step further, for 
he assigned to them the highest rank, wherein nearly every recent 
1 He says from Oken’s Nuaturgeschichte fiir Schulen, published in 1821, but the 
division is to be found in that author’s earlier Lehrbuch der Zoologie (ii. p. 371), 
which appeared in 1816, 
